In general, the broad, long range objective of the proposed studies is to obtain a better understanding of the structure, organization and biological functions of epiphyseal growth plate cartilage. A combination of histologic and chemical methods will be used to define the structural changes which occur in the components of the intercellular matrix of normal epiphyseal cartilage, growth plate cartilage and calcified cartilage which are directly related to the functional properties of these tissues and to the biological processes involved in growth and development. The definition of the major structural changes which occur in the components of the intercellular matrix of growth plate and calcified cartilage should provide a basis for demonstrating defects in crucial structural modifications associated with disorders of growth and development.